The film begins with nothing less moving than the birth of a human consciousness – specifically, Riley’s, a baby girl who’s being cradled in the arms of her mother and father. In an abstract space, a yellow sprite called Joy (voiced by Amy Poehler) emerges into a spotlight, and presses a single button on a polished stand. Back outside, the baby’s eyes light up, and she giggles. Her parents’ hearts melt in an instant. Riley’s life has begun.

Most of Inside Out plays out in these two zones simultaneously: real life, where Riley is now 11 years old and moving with her family from rural Minnesota to San Francisco, and within her Headquarters, where Joy has been joined by Sadness (Phyllis Smith), Disgust (Mindy Kaling), Fear (Bill Hader) and Anger (Lewis Black), whose job it is to guide Riley’s decision-making in the outside world.

The film devises an detailed system whereby Riley’s experiences are turned into glassy, spherical memories which go on to shape her growing personality.